'The impact on a family is cataclysmic'
In the five years up to December 2018, the PSNI received more than 60,000 reports of missing persons in Northern Ireland.
The vast majority of people reported missing turn up - 80% are usually found within the first 24 hours.
But 58 people are still considered as long-term missing persons cases, while 119 have been recorded as having died - some by taking their own lives.
Northern Ireland has a higher suicide rate than other nations of the UK and the Republic of Ireland.
Finding out a loved one has killed themselves brings an added layer of guilt to the families of those reported missing, says Siobhan O'Neill, a professor of Mental Health Sciences at Ulster University.
"Often, families feel... that they might have been to blame, that they didn't spot the signs," she says.
And for families who still have not found a loved one, this can have a "cataclysmic" effect on their lives, adds Prof O'Neill.
"When you've lost someone and you're searching, that uncertainty has the impact of a trauma on the person's whole sense of existence," she says.
Video journalist: Niall McCracken
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